/Engine/Source/Runtime/Engine/Classes/GameFramework/InputDeviceLibrary.h
Returns the primary input device used by a specific player, or INPUTDEVICEID_NONE if invalid
static [FInputDeviceId](API\Runtime\Core\Misc\FInputDeviceId) GetPrimaryInputDeviceForUser ( [FPlatformUserId](API\Runtime\Core\Misc\FPlatformUserId) UserId )